The invention generally relates to adjustable cushioning systems for articles of footwear.
Conventional athletic shoes include an upper and a sole. The sole is usually manufactured of a material chosen to optimize a particular function of the shoe, for example, cushioning or stiffness. Typically, the sole includes a midsole and an outsole, either of which can include, for example, a cushioning material to protect a wearer""s foot and leg. One drawback with conventional shoes is that the wearer has to select a specific shoe to get optimum performance for a specific activity. For example, the wearer has to use one type of shoe for running and another type of shoe for basketball, because one shoe has more cushioning while the other is stiffer for greater support during lateral movement.
Shoes have been designed that attempt to combine and optimize different functions of sport specific shoes; however, the wearer is still left with a shoe with set functionality that the wearer cannot customize. What may be optimal for one segment of the population is not necessarily optimal for everyone. For example, many shoes are designed with wedges or varying degrees of cushioning across the width of the sole to compensate for pronation or supination. Unfortunately, these shoes are typically limited to compensating for either pronation or supination and the amount of compensation cannot be varied to suit a particular wearer. Furthermore, shoes have been designed that attempt to give a wearer some adjustability with respect to a specific function; however, these shoes may require at least partial disassembly of the shoe and/or the wearer may be limited in the amount of adjustment that can be made.
U.S. Pat. No. 5,875,568, the disclosure of which is hereby incorporated herein by reference in its entirety, discloses a cushioning system including a cylindrical shock-absorbing insert located in a heel of a shoe. Similarly, U.S. Pat. Nos. 4,430,810 and 4,573,279, the disclosures of which are hereby incorporated herein by reference in their entireties, also disclose cylindrical inserts located in the heel of the shoe. There are several drawbacks to these cushioning systems. For example, the inserts are isotropic. To adjust the cushioning properties of an isotropic insert, the wearer has to remove the insert and replace the insert with another insert having different cushioning properties. The ""568 patent discloses rotating the insert to xe2x80x9crenewxe2x80x9d the cushioning effect of the insert, but the cushioning effect is the same no matter what orientation is selected. In addition, the inserts can xe2x80x9cturnxe2x80x9d during use, because there is no mechanism for locking the inserts against rotational movement during use.
There is, therefore, a need for a shoe that the wearer can easily, repeatedly, and securely customize. Such a shoe should give the wearer the ability to make numerous adjustments to the functional characteristics of the shoe, for example, increased cushioning, compensation for pronation, compensation for supination, etc.
The invention is directed to adjustable cushioning systems for articles of footwear that can be customized by a wearer. The systems include one or more cushioning inserts having an anisotropic property afforded, for example, by a multiple density construction. The systems may also include structural support elements that provide additional stability and support to the foot. The wearer can adjust the degree of cushioning by rotating the insert within the shoe. Alternatively, the insert could be moved, flipped, or otherwise displaced relative to the shoe to adjust the degree of cushioning. The wearer could also remove the insert and replace the insert with a new and/or different insert. In addition, the insert can be locked in a predetermined position to maintain a specific performance characteristic.
In one aspect, the invention generally relates to an adjustable cushioning system for an article of footwear. The system includes an insert adapted to be received in an aperture formed in a sole of the article of footwear and a locking mechanism disposed proximate the insert for maintaining the insert in a predetermined position or orientation. The insert has an anisotropic property about a longitudinal axis thereof and can be reoriented rotationally in the article of footwear to modify a performance characteristic thereof. The anisotropic property may be compressibility, resiliency, compliancy, elasticity, damping, energy storage, stiffness, or combinations thereof. In various embodiments, the insert is made of a multiple density foam. In another embodiment, the insert may include a skeletal element. In yet another embodiment, the insert is made of a combination of a skeletal element and a multiple density foam. Alternatively, the insert could be made of a first material having a first hardness, a second material having a second hardness, and a third material having a third hardness, for example.
In another aspect, the invention relates to an article of footwear including a sole and an adjustable cushioning system. The system includes an insert adapted to be received in an aperture formed in the sole of the article of footwear and a locking mechanism disposed proximate the insert for maintaining the insert in a predetermined orientation. The insert has an anisotropic property about a longitudinal axis thereof and can be reoriented rotationally in the article of footwear to modify a performance characteristic thereof. The anisotropic property may be compressibility, resiliency, compliancy, elasticity, damping, energy storage, stiffness, or combinations thereof. The system can be located in a heel region and/or a forefoot region of the sole of the article of footwear. In one embodiment, the sole includes an outsole and a midsole, and the insert is disposed at least partially within the midsole of the article of footwear.
In one embodiment, the locking mechanism includes a lever coupled to the insert for rotatably positioning the insert and a mating groove for receiving and maintaining the lever and the insert in a predetermined position. The groove may be disposed in a casing disposed about an end of the insert. Alternatively, the groove could be disposed in a portion of the sole or another structural element disposed within the sole. The lever has a locked position and an unlocked position. The locking mechanism may further include a second mating groove for receiving and maintaining the lever in a second predetermined position. The locking mechanism may also include a detent and an engagement mechanism disposed adjacent the detent. The engagement mechanism has a notch that is engageable with the detent to help maintain the orientation of the insert and/or to indicate to a wearer the position of the insert. The locking mechanism may include a visual position indicator, an audible position indicator, or both. The locking mechanism may be at least partially disposed within a retainer ring circumscribing an end of the insert. The locking mechanism may be disposed on a medial side, lateral side, or heel portion of the article of footwear.
In additional embodiments, the adjustable cushioning system includes a casing disposed in the sole and defining a recess for receiving the insert. The casing may be a retainer ring that circumscribes an end of the insert. The adjustable cushioning system may include a second casing. The second casing may be a retainer ring that circumscribes an opposite end of the insert. In addition, the casing could be a first plate disposed above the insert and a second plate disposed below the insert and coupled to the first plate at an end thereof. In addition, the adjustable cushioning system may include a second insert adapted to be received in the aperture formed in the sole of the article of footwear and a second locking mechanism disposed proximate the second insert for maintaining the second insert in a predetermined position. The second insert has an anisotropic property about, a longitudinal axis thereof and can be reoriented rotationally in the article of footwear to modify a performance characteristic thereof. The second insert may be oriented generally parallel to the first insert.
In additional embodiments, the insert may include a shaft generally longitudinally disposed therein. The shaft may be used to facilitate insertion, removal, and reorientation of the insert, for example. The insert may have a generally cylindrical shape and may define one or more generally longitudinally disposed apertures. The insert may further include a cap and/or an orientation indicator disposed on an end thereof. In still other embodiments, the insert includes an internal support and an external cushioning element disposed about at least a portion of the internal support. The external cushioning element may have a lower durometer than the internal support. The insert may include an axle disposed within the internal support. Also, the internal support may include a rib disposed on an external surface thereof. The internal support may have a cross-section, such as polygonal, arcuate, or combinations thereof, and may span an entire width of the insert.
In yet another aspect, the invention generally relates to an adjustable cushioning system for an article of footwear. The system includes an insert adapted to be received in an aperture formed in a sole of the article of footwear. The insert has an anisotropic property about a longitudinal axis thereof and can be reoriented rotationally in the article of footwear to modify a performance characteristic thereof. The anisotropic property can be selected from the group consisting of compressibility, resiliency, compliancy, elasticity, damping, energy storage, and stiffness. The insert can include an internal support and an external cushioning element disposed about at least a portion of the internal support. In one embodiment, the external cushioning element has a lower durometer than the internal support.
In various embodiments, the adjustable cushioning system includes an axle disposed within the internal support. The insert can have essentially any cross-sectional shape, such as polygonal, arcuate, or combinations of polygonal and arcuate elements. In the present application, the term polygonal is used to denote any shape including at least two line segments, such as rectangles, trapezoids, and triangles. Examples of arcuate shapes include circular and elliptical. In a particular embodiment, the insert has a generally cylindrical shape. The insert can include a handle disposed on an end thereof. Further, the external cushioning element and/or the internal support can include a generally longitudinally disposed aperture. In one embodiment, the aperture can be substantially parallel to the internal support. In another embodiment, the external cushioning element and/or the internal support can include a second generally longitudinally disposed aperture. In additional embodiments, the internal support can include one or more ribs disposed on an external surface thereof. The internal support can have a cross section that is polygonal, arcuate, or combinations thereof. The internal support can span substantially an entire width of the insert.
In addition, the adjustable cushioning system can include a structural support casing disposed in a sole of the article of footwear and defining a recess for housing the insert. The structural support casing may have a generally recumbent V or U-shaped cross-sectional profile. Furthermore, the adjustable cushioning system can include a second insert. The second insert can include an internal support and an external cushioning element disposed about at least a portion of the internal support. In an embodiment of the invention that includes a structural support casing, the second insert can be disposed in a second cylindrical recess in the structural support casing.
Furthermore, the adjustable cushioning system can be generally longitudinally disposed within the article of footwear and can extend from about the heel region to about an arch region of the article of footwear. Alternatively, the adjustable cushioning system can be generally laterally disposed within the article of footwear and can span substantially an entire width of the article of footwear. In addition, the insert can be diagonally disposed within the article of footwear. The inserts may be removable from the article of footwear so they can be replaced when they wear or when different inserts having different characteristics are desired.
These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.